Sanyo CE26LD81-B TV Troubleshooting

[MrF]

Hi guys
I just acquired a Sanyo TV for free (built by Vestel it seems though according to the maker on some of the boards inside :/ )
Last owner says it was put in the shed as it wasn't coming on for up to 30 minutes so they bought another TV and stuck this one in the shed a while back wrapped in a blanket.
Got it home, let it warm up, cleaned the dust etc off it, opened it up, found a quantity of GLuxon caps, HEC caps and Capxon caps.
Swapped out some of the GLuxon caps on the power board as I have some 16V and 35V 1000uF Panasonic FM caps, mainly swapped like for like, but there was space on 2 for the 35V caps so used them instead.

Hopefully the pics are ok and not too many. Apologies if too many.

Plug it in and the LED on the front lights up blue, turn it off standby and the screen stays black and the LED goes out (LED is meant to go out according to the manual)

Left it a few minutes, nothing, hitting the standby button doesn't return it to standby. Have to unplug and re-plug in to get back to standby.

Tried a hairdryer across the boards to see if it would come on, however no signs of life...

Also shone a torch but nothing showing on the screen at all.

Noticed on the powerboard that the large black capacitor has broken loose of the glue holding it down and there's brown discolouration on the board just below the terminals for the large cap.

Checked all the connections and everything seems secure.

Next steps?

Thanks in advance

[drpj23]

Re: Sanyo CE26LD81-B TV Troubleshooting

What are the voltages coming out of the PSU when the TV is "on"?

[MrF]

Re: Sanyo CE26LD81-B TV Troubleshooting

Will check,
Suggested test points? (as I'm not sure where to test it, electronics knowledge....not so much currently)

Outputs are the flat cables that are on the bottom left of the board (as shown on pic 2) (Well as far as I know)

I'm going to take some pics of the bottom of the board also as I'm not wholly sold on the standard of soldering from the factory and I'd like someone else to take a look.

Thanks

[tom66]

Re: Sanyo CE26LD81-B TV Troubleshooting

Two 15n caps (red) near main transformer. Replace these on 90% of this chassis and it fixes it. Try freeze spraying them first.

[MrF]

Re: Sanyo CE26LD81-B TV Troubleshooting

Tom,
Ok I see what you mean.
Might just swap them out (though will see if I can find my can of freeze spray first.)
Another thing to add to the RS order list.
Cheers mate.

Edit: Just tried freezing them, no difference, checked power is reaching the board and meter shows 247VAC (substation is just round the corner so at the higher end)

[tom66]

Re: Sanyo CE26LD81-B TV Troubleshooting

The originals were insufficient just, 400V or 630V, depending on what was cheapest on the day. Use at least 800V, preferably 1000V. Transients are what kill these caps.

[MrF]

Re: Sanyo CE26LD81-B TV Troubleshooting

Thanks,
Any suggestions / example links to decent replacements for those items?

[tom66]

Re: Sanyo CE26LD81-B TV Troubleshooting

http://uk.farnell.com/panasonic/ecwh...?Ntt=15nf+800v

[MrF]

Re: Sanyo CE26LD81-B TV Troubleshooting

Thanks, much appreciated.
RS don't stock them seemingly, so will just order from Farnell...appreciated.

[MrF]

Re: Sanyo CE26LD81-B TV Troubleshooting

Almost killed the board.....overheated 2 pads and burnt them....badly
though I think I've rescued them...managed to make out where the traces run to next and bridged the legs from the component on the burnt pads to the next component's solder pads on the respective traces.
Am I right in thinking that should work ok?

[tom66]

Re: Sanyo CE26LD81-B TV Troubleshooting

If you unsure, post a picture. It's a single layer board, so essentially any damage is repairable. (That's not an invitation... )

[MrF]

Re: Sanyo CE26LD81-B TV Troubleshooting

Ok so 1&3 show the damage from different angles (yeah I burned that right off...maplin cheap 40W soldering iron though, gets so hot the handle gets incredibly hot....might now invest in something a little better built..)
9&10 show the repair attempt
12 is the location on the top side of the board, little red capacitor

14 is something (crystal resonator?) i found laying on the floor (pretty sure it fell out when I opened the TV as its missing in the first shots....would that being missing also stop it powering on?)

15 is where its from (IDTV card / CAM)

[tom66]

Re: Sanyo CE26LD81-B TV Troubleshooting

That crystal resonator could cause the DTV to not work. Odd that it would just fall out!

Those pictures don't look like the area around those poly caps... never seen that before, maybe different design?

C878/C877 are what needs replacement. Have you removed those?

[MrF]

Re: Sanyo CE26LD81-B TV Troubleshooting

Yep did that and then got cocky and C836 is the one I fried......
(If C878 and C877 are at the top left of the board C836 is just to the right of them between some aluminium radial caps)

[tom66]

Re: Sanyo CE26LD81-B TV Troubleshooting

Here is a schematic of the PSU.


C836 is a 100nF poly capacitor (I think?)

[MrF]

Re: Sanyo CE26LD81-B TV Troubleshooting

I'm still learning how to read component markings
This resonator:
CREC is the maker (china something or other)
4.000000Mhz is the frequency (understood that without issue)
0703 though I'm not sure on if its of any consequence or just something to do with CREC

[MrF]

Re: Sanyo CE26LD81-B TV Troubleshooting

I wasn't sure as it had next to no markings on it, so I just resoldered it and thats when the burn happened...
Thanks for the PDF....very handy.

I looks like it just snapped off at some point,

[tom66]

Re: Sanyo CE26LD81-B TV Troubleshooting

0703 is just a date code either 7th week 2003, or 7th month 2003 (or possibly the other way around in 2007) -- you would need the original manufacturer's datasheet to be sure but all that really matters is 4.0000... MHz.

[MrF]

Re: Sanyo CE26LD81-B TV Troubleshooting

Cheers.
I'm a domestic electrician and IT Installer to trade, so this is new ground.
Thanks for your help its much appreciated.

[MrF]

Re: Sanyo CE26LD81-B TV Troubleshooting

Ok so caps ordered, with some other stuff also...£24 lighter in the wallet...lol this TV had better gets its ideas in order and work or I'll be rather unimpressed with it....